Lubricant



Reiuued Apr. 4, 1944 22.404 wnmcan'r Charl'es D. Kelso, Princeton, N. 1., and Lawson W. Mixon, Hammond, Ind., assignors to Standard Oil .Company, Chicago, Ill-"a corporation of Indiana I I No Drawing. Original Natale-.690, dated April 6, 1943, Serial No. 424,967.!)ecember 30, 1941.

Application for N 0. 520,706

31 Claims.

.in lubricating oils and in general are effective in inhibiting corrosion to metal surfaces in contact with such oils. However, under certain conditions these reaction products, particularly the neutralized reaction products, do not inhibit corrosion to the desired degree, and in some cases may induce corrosion.

We have discovered that lubricant compositions containing these neutralized reaction products of a phosphorus sulfide and an olefin can be' made substantially non-corrosive by adding in combinarcissue Februaryl, 1944, Serial Darafiln waxes having at least about 20 carbon atoms per molecule, and melting points upwards from about 90 F. and preferably within the range of from about 120 F. to about 140 F.

To obtain the halogenated paraflin wax, for example, chlorinated paramn wax, we introduce chlon'ne into the wax, maintained in a molten state, until the wax has a chlorine content of from about'8% to about The chlorinated wax product is a mixture of unchlorinated wax, monochlor wax and polychlor wax. This chlorinated product may be used as such, but it is advantageous to use the substantially -mon0chlor. wax fraction. The monochlor wax fraction can be segregated from the unchlorinated wax and the polychlor wax fractions by taking advantage of the differences in the melting points of the tion with the latter a small amount of elemental sulfur or an organic sulfur compound, particularly an organic sulfur compound capable of being decomposed to give free sulfur at the temperature to which the lubricant is subjected during use. Examples of suitable organic sulfur compounds are sulfurized mineral oils, sulfurized nondrying animal and vegetable oils such as sulfurized lard oil, sulfurized corn oil and the like, sulfurized olefins, sulfurized olefin polymers, such as sulfurized isobutylene polymer, sulfurized sperm oil, etc.

The preferred olefins suitable for thepreparation of the hereindescribed phosphorus sulfide reaction products are olefins having at least 20 carbon atoms in the molecule, of which from about 12 carbon atoms to about 18 carbon atoms, and preferably at least 15 carbon atoms, may be in a long chain. Such olefins cam be obtained by the dehydrogenation of paraflins, such as by the cracking of paraffin waxes, or by the dehalogenation of alkyl 'halides, prefer'ably long chain alkyl halides, particularly halogeated paraflln waxes.

The olefins obtained by dehalogenation of long chain a-lkyl halides are preferably those obtained by dehalogenation of monohalogenated waxes, such as, for example, those obtained by deohlorination of monochlor paraflin wax. The alkyl halides are decomposed to yield olefins according to the reaction in which n is a whole number, preferablyio or more, and X is an halogen. We prefer to employ various fractions, since the melting point of the unchlorinated wax is greater than that of the monochlor wax, and the melting point of the latter is greater than that of the polychlor wax.

Thus, the monochlor paraffin wax can be separated from the unchlorinated and the polychlor wax fractions by means such as sweating, fractional distillation, solvent extraction, solvent precipitation, and fractional crystallization.

The high molecular weight olefins are obtained by removing the halogen as hydrogen halide from the halogenated paraflin wax. For example, the corresponding olefin is obtained from the monochlor parafiin wax by removing the chlorine from the latter as hydrogen chloride. 'The monochlor wax can be dechlorinated by heating to a temperature of from about 200 F. to about 600 F. in the presence of a dechlorinating agent such as an alkali metal hydroxid or an alkaline earth metal hydroxide or oxide. Other alkaline inorganic or organic materials can also be used. The chlorine can also be removed from the chlorowax by heating the same for a prolonged period in the absence of any dechlorinating agent. After the dehalogenation has been completed the olefin so obtained can be further purified by removing the dehalogenating agent by means of filtration or by other suitable means.

We may also employ olefin polymers, those having molecular weights above preferably about 300.

As olefinic starting materials for the production of such polymers, we may employ the individual olefins themselves, mixtures of olefins or mixtures of olefins and non-oleflnic compounds. For example, the olefinic starting material. may be butylenes, amylenes, refinery gases containing normally gaseous olefins and cracked distlllates or other relatively low-boiling hydrocarbon mix- 2 tures containing normally liquid olefins and mix-, tures of normally liquid olefins, containing substantial amounts of dissolved normally gaseous mono-olefins, preferably iso-mono-olefins, such as isobutylene and isoamylene and/ or the copolymers obtained by the polymerization of hydrocarbon mixtures containing low molecular weight isoolefins and normal olefins, preferably those of less than six carbon atoms.

The mono-olefin polymer to be treated may be thepolymer resulting from the polymerization of low molecular'weight iso-mono-olefins such as isobutylene and isoamylene and/orthe copolymers obtained by the polymerization of hydrocarbo'n mixtures containing low molecular weight iso-mono-olefins and normal mono-olefins such as those of less than six carbon atoms, and preferably those of four carbon atoms. The

polymer may be, obtained by the polymerization of these mono-olefins or mixed mono-oleflnsv in the presence of a catalyst such as sulfuric acid, phosphoric acid, boron fluoride, aluminum chlo ride or other similar halide catalyst of the Friedel- Crafts type.

The polymers employed'are preferably monoolefin polymers, in which the molecular weight ranges from about 150 to about 50,000 or more, y and preferably from about 500 to about 10,000.

These polymers can be obtained,-for example, by the polymerization in the liquid phase of isooleflns such as isobutylene or hydrocarbon mix- -tures containing the same at a temperature ,of .from about -80 F. to about 100f F., in the presence of a catalyst such as boron fluoride. In the preparation of these polymers, we employ, for example, .liq'uid isobutylene or a hydrocarbon mixture containing isobutylene, butane, and butylene, recovered from petroleum gases, especially those gases produced in the cracking of petroleum oils in the manufacture of gasoline. This light fraction may contain from about 10% to about isobutylene, the remainder being principally butanes and normal butylene.

We mayalso employ as the starting material the polymer obtained by polymerizing unsaturated hydrocarbons resulting from the vapor phase cracking of parafiln waxes in the presence of aluminum chloride which .is fully described in United State Patents Nos. 1,995,260, 1,970,002 and 2,091,398. Still another type of olefin polymer which may be employed is the polymer resulting from the treatment of vapor phase cracked gasoline and/or gasoline fractions with sulfuric acid or solid absorbents such as fuller's earth whereby unsaturated polymerized hydrocarbons are removed. Also contemplated within the scope of our invention is the treatment with phosphorus sulfide of the polymers resulting from the voltolization of hydrocarbons as described, for example, in United States Patents Nos. 2,197,768 and 2,191,787.

Other olefin's which can be employed are the high molecular weight copolymers of a low molecular weight olefin and a non-aromatic hydrocarbon having the general formula CnH21l-x in which a: is 2 or a multiple of 2, the copolymer having a controlled degree of unsaturatiom It is to be understood that the expression "nonaromatic hydrocarbon having the general formula CnHzn-z in which a: is 2 or a multiple of 2 embraces the substitution products of these hydrocarbons, such as, for example, chloroprene. By reacting a phosphorus sulfide with the copolymer, having the desired degree of unsaturation, reaction products are obtained which have a higher phosphorus content than is otherwise obtainable by reacting a phosphorus sulfide with amono-olefin polymer, and which are more stable than the reaction products of a phosphorus sulfide and a diolefin polymer.

The copolymer base is prepared by controlled copolymerization of a low molecular weight olefin and a non-aromatic hydrocarbon of the above type in the presence of a catalyst of the Friedel- Crafts type. The low molecular weight olefin is preferably an isoolefin or atertiary base olefin preferably one having less than 7 carbon atoms per molecule. Examples of olefins which can be suitably employed are isobutylene, Z-methyibutene-l, 2-ethylbutene-l, secondary and tertiary base amylene, hexylene and the like, isobutylene being preferred, however.

Examples of the non-aromatic hydrocarbons falling within the above general formulaare the conjugated. diolefins-such as butadiene, isoprene, cyclopentadiene, 2,3-dimethylbutadiene-1,3, pentadiene-1,3, heXadiene-2,4, and the substituted diolefins such as chloroprene and the like, the diolefins such as dialkyls, for example, diisobutenyl, and the like, in which the double bond is not conjugated; and the acetylenes such as acetylene vinyl acetylene and the like; and the .ibstitution products of the foregoing.

The copolymerization of the isoolefin and the diolefin is preferably carried out in the presence of aluminum chloride or boron fluoride, although other Friedel-Crafts type catalyst such as aluminum bromide, zinc chloride, zirconium chloride andthe like can be employed. 1

In the preparation of the copolymer base which preferably has a molecular weight of from about 1,000 to about 30,000 and contains from about 2% to about 20% butadiene, from about 20% to about 60% by weight of the diolefin is reacted with the olefin at a low temperature ranging from about 32 F. to aboutv -150 F. and preferably from about 10 F. to about 130 F. The polymerization is conducted in the presence of v a diluent and preferably a diluent which is capable of functioning also as a refrigerant such as a liquefied normally gaseous hydrocarbon such as, for example, liquefied ethylene, liquefied propane, liquefied butane and the like. Alkyl halides such as methyl chloride can also be used.'

In carrying out the polymerization the reaction chamber is first cooled to the desired low temperature by adding thereto a sufficient amount of the liquefied normally gaseous hydrocarbon. The diolefinsare then added to the reactor followed by the addition of the isoolefin. After the isoolefin has been added the catalyst,

- preferably in solution in a suitable solvent such as, for example, a low molecular weight allcyl halide, i then added to the mixture. It is highly desirable to provide for rapid mixing of the reaction mass to obtain a uniform product. The polymerization reaction is permitted to proceed to a polymer yield of from about 50% to about in order to obtain polymers of the desired molecular weight and of the desired degree of unsaturation. The'reaction can be stopped at the desired yield by adding to the reactor a material capable of quenching the reaction. Suitable quenching agents are alcohols, ethers, ketones and the like; ethyl alcohol is preferably employed for this purpose.

from about 1% to about 50% and preferably fromabout 5% to about 25% (by weight) Of the reactants employed. It is advantageous to maintain a non-oxidizing atmosphere, such as, for

example, an atmosphere of nitrogen, above the reaction mixtures. Usuall 'it is preferable to use an amount of the phosphorus sulfide that will completely react with the olefin so that no further purification becomes necessary. However, excess phosphorus sulfide may be used and separated from the product after heating is discontinued by filtering or by diluting with a solvent such as hexane, filtering, and subsequently distillin -off the solvent. If desired,'the reaction product may be further treated b blowing with steam at an elevated temperature of from about 200 F. to about 600 F. to improve the odor thereof.

The phosphorus sulfide-olefin reaction product normally shows a titratable acidity. This titratable acidit is neutralized when the reaction product is treated with a basic reagent. The

phosphorus sulfide-olefin reaction product when neutralized with a basic reagent containing a metal constituent is characterized by the presence or retention of the metal constituent of the reagent. heavy metal constituent may be introduced into the neutralized product by reacting the same with a salt of the desired heavy metal.

The term neutralized phosphorus sulfide-olefin reaction product as usedherein means a.

phosphorus sulfide-olefin reaction product having at least about 1% of its titratable acidity reduced by the reaction with a basic reagent, and includes the neutralized phosphorus sulfideeolefir'i reaction products containing a metal constituent resulting from said neutralization or resulting from the reaction of a heavy metal salt with the phosphorus sulfide-olefin reaction product with a basic reagent. 7

The neutralized phosphorus sulfide-olefin reaction product may be obtained by adding to the reaction product a. suitable basic compound such as a hydroxide, carbonate, or an oxide of an alkaline earth metal or of an alkali metal, preferably potassium hydroxide or sodium hydroxide. Other basic reagents may be used, such as, for example, ammonia, or alkyl 'or aryl substituted ammonia, such as amines. As aforesaid when the phosphorus sulfide-olefin reaction product is basicity may be obtained.

heavy metal with the phosphorus sulfide-olefin reaction product which has been treated with a basic reagent.

It will be understood that when the neutralization is accomplished with a. polyvalent basic material, such as lime, a product having excess In accordance with the present invention the foregoing neutralized reaction products are emplayed in lubricants in small amounts in combination with small amounts of the aforementioned organic sulfurgbearing compounds or sulfur. The neutralized phosphorus sulfide-olefin or olefin polymer reaction product is employed in amounts within the range of from about0.001%

- to about 10% and-preferabl from about 0.01%

Other metal constituents such as a neutralized with a basic compound containing a stituent such as, for example, tin, titanium, aluminum, chromium, cobalt, iron and the like may be obtained by reacting a salt of the desired to about 3%, while the organic sulfur-bearing compound or sulfur is employed in amounts sufficient to give a free sulfur content within the range of from about 0.001% to about 5%, Dreierably from about 0.002% to about 3%.

The improvement obtained when a small amount of a sulfur-bearing organic compound or sulfur is used in combination with a. neutralized phosphorus sulfide-olefin or olefin reaction product is illustrated by the corrosion dat presented in the following table. The data presented therein are those obtained by immersing a. copper strip having an area of about 6.5 square centimeters and a lead strip having an area of about 3.5 square centimeters in 380 cc. of oil malntained at a temperature of 315 F. the test piece being suspended on a glass rod which-is rotated at R. P. M, At intervals of 24, 48 and 72 hours th lead test pieces are removed, cleaned, dried and the loss in weight in milligrmns noted. The

following oils were tested by the abov method:

up o w I E+0.1% sulfurized .mineral oil containing about 1.5% free sulfur. G. E+0.25% sulfurized mineral oil containing about 1.5% free sulfur- H. E+1% sulfurized mineral oil containing about 1.5% free sulfur.

Table I Lead corrosionloss in milligrams nil 24 his. 48 hrs. 72 hrs.

11 1. 325 sis-s C 11.1 1.8 21.9 1.0 9.3 37.11 1-: 111.3 715 F 0.8 as 41.7 (1,. 1.1 3.1 01.1 li 0.4 7.2 50.2

The above data show decrease in corrosipn affected by the use of a specific organic sulfur ompound, employed in combination with a. neutralized olefin polymer-phosphorus sulfide reFction product in mineral oil. The improvement obtained and the degreeof improvement eflected applied to mineral lubricating oils, our invention contemplates the use of sulfur-beefing organic compounds of the type described or elemental sulfur in combination with the neutralized reaction roducts of a phosphorus sulfide and an olefin or olefin polymer, in products other than the mineral lubricating oils such as, for examp e, fuel oils, insulating oils, non-drying vegetable and animal oils, synthetic oils, greases and the like.

The term olefin as used in the P rase "P phorus sulfide-olefin reaction produc as applied herein and in the appended claims includes efins, olefin polymers and olefin copolymers.

While we have described our invention by reference to various representative constituents and have illustrated the sameby reference to specific examples thereof, our invention is not to be lim-. ited to the various representative compounds named or to the specific examples given but includes within its scope such modifications as come within the spirit of the appended claims.

We claim:

1. A lubricant composition containing an oil and a small amount of a sulfur compound selected from the class consisting of elemental sulfur and an organic sulfur compound capable of decomposing to form free sulfur, and a small amount of the neutralized phosphorus and sulfurphosphorus pentasulfide and an isobutylene polymer having a molecular weight of at least about 300.

'l. A lubricant composition as described in claim 8 in which the neutralized reaction product contains a metal vconstituent.

.8. A lubricant as described in claim 6 in which the neutralized reaction product. contains potassium.

phosphorus and sulfur-containing reaction prodnot of phosphorus pentasulfide and an isobutylvone polymer having a molecular weight of at least about 300, said neutralized reaction product containing potassium.

12. A lubricant comprising a mineral oil and in combination therewith a small amount of an organic sulfur compound capable of decomposing to form free sulfur and a small amount of the neutralized phosphorus and sulfur-containing recontaining reaction product of a phosphorus sul- 2. A lubricant composition containing an oil and asmall amount of a sulfur compound selected from the class consisting of an organic sulfur compound. and elemental sulfur, and a small amount of the neutralized phosphorus and sulfurcontaining reaction product of a phosphorus sulfide and an olefin having at least 20 carbon atoms in a molecule of which from about 12 carbon atoms to about 18 carbon atoms are in a long chain.

3. A -1ubricant composition containing an oil and a small amount of a sulfur compound selected from the class consisting of an organic sulfur compound and elemental sulfur, and a small amount of the neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefin polymer having a molecular weight of at least about 300.

4. A lubricant composition containing an oil and a small amount of a sulfur compound selected from the class consisting of an. organic sulfur compound and elemental sulfur, and a action product of a phosphorus sulfide and an olefin.

13. A lubricant comprising a mineral oil,- a small amount of an organic sulfur compound capable of forming free sulfur upon decomposition and a small amount of the neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an isobutylene polymer having a molecular weight of at-least about 14. A lubricant as described in claim 13 in which the organic sulfur compound is a sulfurized mineral oil.

15. A lubricant composition containing a mineral oil, a small amount of an organic sulfur com- 7 pound capable of decomposing to form free sulfur and a small amount of the neutralized phosphorus and sulfur-containing reaction product of a. phosphorus sulfide and an olefin having at least 20 carbon atoms in a moleculeof which from about 12 carbon atoms to about 18 carbon atoms are in a long chain.

16. A lubricant comprising a mineral oil, a.

small amount of an organic sulfur compound capable of forming free sulfur upon decomposition and a small amount of the neutralized phosphorus and sulfur-containing reaction product small amount of the neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an isobutylene polymer having a molecular weight of at least about 300.

5. A lubricant composition containing an oil and a small amount of a sulfur compound selected from the class consisting of an organic sulfur compound and elemental sulfur and-a small amount of the neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a copolymer of a mono-olefin and a non-aromatic hydrocarbon having the general formula CnHZn-a: in which x is 2 or a, multiple of 2.

6. A lubricant composition containing an oil and a small amount of an organic sulfur compound capable of decomposing to form free sulfur and a small amount of the neutralized phos phorus and sulfur-containing reaction product or of a phosphorus sulfide and a copolymer of a monoolefin and a non-aromatic hydrocarbon having the general formula CnHZn-z in which 2 is 2 or a multiple of 2.

17. A lubricant as described in claim 16 in which the mono-olefin is isobutylene and the non-aromatic hydrocarbon having the general formula CnH2n-z is butadiene.

18. a lubricant comprising a mineral oil, a small amount of an organic sulfur compound and a smallamount of the neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a copolymer of isobutylene and chloroprene, said copolymer having a molecular weight of at least about 1,000.

19. A lubricant comprising a mineral lubricating oil, a small amount of a sulfurized oil and a small amount of the neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefin polymer havin'g a molecular weight of at least about 3,000.

potassium.

23. A lubricant as described in claim 20 in which the neutralized reaction product contains sodium. v

24. A lubricant as described in claim 20 in which the neutralized reaction product contains calcium.

25. The method of inhibiting corrosion and the formation of deposits of the type of sludge, carbon and varnish in an internal combustion engine during use comprising lubricating with an oil normally susceptible to form sludge, carbon and varnish in an internal combustion engine during use and in combination therewith small amounts of an organic sulfur compound capable of forming free sulfur upon decomposition and the phosphorus and sulfur-containing product obtained by the process comprising reacting a phosphorus sulfide with an olefin and neutralizing said product with a basic reagent, said organic sulfur compound being used in amounts sufficient to inhibit corrosion and said neutralized reaction product being used in amounts suilicient to inhibit the formation of deposits of bon and varnish.

26. A new composition of matter comprising: an oil; a sulfur compound selected from the class consisting of elemental sulfur and an organic sulthe type of sludge, car- I fur compound; and, the neutralized phosphorus and sulfur-containing reaction phosphorus sulfide and an olefin.

27. A new composition of matter as described in claim 26 in which the neutralized reaction product contains a metal constituent.

28. A new composition or matter as described in claim 26 in which the neutralized reaction product contains potassium.

29. A new composition of matter as described product of a in claim 26 in which the neutralized reaction product contains sodium.

30. A new composition of matter as described in claim 26 in which the neutralized reaction product contains calcium.

' 31. A new composition or matter comprising: an oil; a sulfur compound selected from the class consisting of elemental sulfur and 'an organic sulfur compound; and, a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a mono-olefin polymer.

CHARLES D. KELSO. LAWSON W. MDION. 

